docs: update README with config file usage

Replace command-line credential options and environment variables
with config file documentation. Add the new `running` command and
update all examples to use the required --server option.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -25,48 +25,54 @@ uv run zzpyjenkins --help
 
 ## Configuration
 
-You can provide Jenkins credentials via command-line options or environment variables:
+Create a config file at `~/.config/zzpyjenkins/config.toml` with your Jenkins server configurations:
 
-### Command-line options (preferred)
+```toml
+[work]
+url = "https://jenkins.work.com"
+username = "myuser"
+password = "my-api-token"
 
-```bash
-zzpyjenkins -u https://jenkins.example.com -U username -P token info
+[home]
+url = "http://localhost:8080"
+username = "admin"
+password = "admin123"
 ```
 
-### Environment variables
-
-```bash
-export JENKINS_URL="https://your-jenkins-server.com"
-export JENKINS_USERNAME="your_username"
-export JENKINS_PASSWORD="your_api_token"  # or JENKINS_TOKEN
-```
+Use the `-s/--server` option to select which server to use.
 
 ## Usage
 
 ```bash
 # Show Jenkins server info
-zzpyjenkins info
+zzpyjenkins -s work info
 
 # List all jobs
-zzpyjenkins list
+zzpyjenkins -s work list
 
 # List jobs with filter
-zzpyjenkins list -p "my-project"
+zzpyjenkins -s work list -p "my-project"
 
 # Trigger a build
-zzpyjenkins build my-job-name
+zzpyjenkins -s work build my-job-name
 
 # Trigger a build with parameters
-zzpyjenkins build my-job-name -p BRANCH=main -p ENV=staging
+zzpyjenkins -s work build my-job-name -p BRANCH=main -p ENV=staging
 
 # Get build status
-zzpyjenkins status my-job-name
+zzpyjenkins -s work status my-job-name
 
 # Get specific build status
-zzpyjenkins status my-job-name 123
+zzpyjenkins -s work status my-job-name 123
 
 # Watch build progress
-zzpyjenkins watch my-job-name
+zzpyjenkins -s work watch my-job-name
+
+# List running jobs
+zzpyjenkins -s work running
+
+# Show only count of running jobs
+zzpyjenkins -s work running -c
 ```
 
 ## Development